4X4 I CANNOT GET THIS TRUCK THROUGH SMOG

1986 Toyota Pickup • 4 cylinder 4WD Manual • 150,000 miles

1986 Toyota Pickup 4x4 mileage: 150,000. I cannot get this truck through smog. The readings are great at Idle, but at 2500 rpm there is 2% CO 30 ppm HC 1% O2 and 13. 5% CO2. I know this is a rich running condition. I have changed the 02 sensor, and nothing. Before I replace the carburetor, I wanted to ask you guys. Thanks